Ring counter with parallel input to cathodes from pulse standardizer



p 1964 J. P. ECKERT, JR. ETAL 3,149,285

RING CQUNTER WITH PARALLEL INPUT To CATHODES FROM PULSE STANDARDIZEROriginal Filed June 26, 1947 INVENTORS John Presper Eckerf,Jr. John W.Mauchly ATTORNEY United States Patent 0 ice 'l" is invention is adivision of our application SN. No. $120,635,

757,158, filed June 26, 194-7, now Pater and relates to electronicmechanism f storing electrical signals representative or c. his data,and more particularly to improved apparatus and method of operation forcounting and storing successive electrical pulses at high frequencywhereby the pulses may be ed and regi tered with maximum accuracy.

ough the pulse register is adapted for receiving any intelligence whichmay be transmitted by elec cal pulses, the disclosed embodiment showsthe register adapted to receive data based on the decimal system ofnumerical notation. A plurality of vacuum elec ron tubes, eachrepresenting a digit in a denominat: nal orer of the decimal system ofnumerical notation, are so coupled in a network as to be responsivestep-by-step fashion to each of a plurality of filiClIiCnl impulsescommonly impressed on such network at high frequency.

The disclosed embodiment of an electrical pu se counter and storer, ormemo= n a plur of different forms, all 61 A ing the same basicprinciple, in our copending application for US. Letters Patent, SerialNumber 757,153, filed lune 26, 1947, for Electronic Numerical integratorand Computer, termed Eniac, now Patent No. 3,120,606.

A serious obstacle to the successful construction of an electroniccomputing machine of satistacto r accuracy and reliability has been thetendency for para to signals and other manifestations to develop, due tothe reactances inherent in interconnecti imporpah rent of the properresponse of the machine to the significant pulses for either numericaleffect, or for control and timing of com' .1-.ative operations.

Anoth r difficulty which it is a purpose of the invention to overcome ina novel way, is tendency for signals to become distorted as topotential, 0 tion, and shape (as recorded by the oscilloscope) byinterferences, capacitative or inductive. in this direction a novelapproach has been effected by not transn properly timed pulses ofnumerical or control signlncance through the various conductors from theinitiating device directly to the one which is to respond, but insteadto stimulate operation of a gate or pulse former device of very definitepulse forming characteristics at the fill of the responding device.

As a consequence of the foregoing, in our invention at each introductionof data to an arithmetic unit, an original shaping of the pulse receivedby that unit is effected by the unit itself.

It is an important aim of the invention to devise a novel means ofpreserving the definite and highly effective form or" signal informationtransm tted to or thro gh the various parts of the system and w ardpulse forms and potentials at all stages of operations and registeringcaused by such pulses.

An object of the invention is to org' of the machine so as to eliminateiunc.-ons or" su h nature that they might be materially aliected by varrtions or" operating conditions such as often occur. The man e the elemnts Eddhghd Patented Sept. 15, 1954 chine is thus adapted to practicallyinfallible operation under varying conditions which extensive experiencehas shown be expected to be manifest in such machines over a reasonableperiod of operation.

For instance, it is an attainment of the invention that electronemission high vacuum tubes such as common triodes or pentodes, used inradio receivers, are made use or" as switching devices in such mannerthat their operation occurs in a condition far from the critical pointbetwee conduction and nonconduction, and so that deten in the tubeelements or the state of the space n over a period of months, will notmaterially affeet the response of the tube to control potentials appliedto the grids as pulses or potentials of substantial values.

it is a related aim to use such tubes as switches or other kineticequivalents in such manner that their function will be either conductingor non-conducting, accoming this by use of the tubes at or close tosaturation conducting state, and with a grid bias well bethe criticalpoint for their non-conducting state.

tatron of a n1 coun ng of pulses of numerical significance is desired,it is a special aim of the invention to evolve novel means by which suchring counters are embodied so as to operate with great certainty andeffectiveness.

An important aim of the invention contributing to its successfuloperation with a minimum of impairment or malfunction mathematically, isto eh'ect intercommunication between units having pulse-responsivecircuits which ,re maintained at widely dlfierent potentials for theirnormal conditions, by the communication of pulses from one such unit toanother such unit without mutual disturbance of their normal potentials,yet in a most definite manner taking full advantage of thebefore-mentioned operations of tubes well below or above cut oil, orwell above minimum con uctance conditions (that is close to thesaturation state of conductance).

l is the basic circuit or" a decade ring counter and stepper ring.

EEG. 2 shows a pulse standardizer circuit.

FIG. 1, to which reference is now made, shows a decade ring counterconstructed according to the present The decade ring counter illustratedis a ten invention. stage (with two tubes per stage) ring counter withten dirrercnt stable states. Each stage has two tubes which will becalled respectively tube A and tube B. Only one tube of each stage isconducting. if tube A is conductthat stage will be said to be in stateA; if tube B is conducting then that will be said to be in state B. Thestable state of the whole ring is with one stage in state B and theother nine stages in state A. The circuits are so arranged that if onestage is in state B and a pulse is received it will go into state A andthe next following stage will go into state B.

The two cathode resistors for tubes in state A and tubes in state B areso chosen as to permit only one mode or" operation, namely, one stage instate B and the other nine stages in state A.

l ulses that step the ring are negative and are introduced on all thecathodes of the tubes A. Such stepping pulses have little eiiect on thestages in state A but causes the cathode requires careful design toobtain reliable operation. Thus, the stepping pulse must be of preciseshape and duration, and the carry-over pulse must over-ride it. This isaccomplished by putting the incoming pulses through a pulsestandardizer, disclosed hereinafter and by using the proper circuitparameters in the decade ring circuit. a

In FIG. 1, the stage is shown in state B, and its neon lamp 106 istherefore lit, since it is connected between the plate of tube A ofstage 0 and the B minus line 108 (conduction of the tubes beingindicated by shade lines).

As A (i.e., tube A of stage 0) is not conducting, its plate voltage ishigh enough to light neon 106 through resistor 109. All the other stagesare instate A, the various circuit potentials being chosen to maintainstability in the condition shown, and therefore the other nine neons areunlit, since the plates of their respective associated tubes are in theconducting condition, and therefore are not in turn raises the voltage(through lead 111) of the grid of A in the usual flip-flop action, whichcontinues until stage 0 is changed over to the A state, and neon 106goes out. At the same time, the rise in potential at the plate of Bcauses a positive pulse to bias the grid of B through lead 101, whichrenders tube B conducting and tube A non-conducting by the sameflip-flop action, thus putting stage .1 into state B and lighting neon107. As B becomes conducting its plate voltage drops, producing anegative pulse on lead 112, but this has no effect on tube B which isnon-conducting. Note'that this counter is shown as a ring counter, thatis, each pulse will change the statefof the next tube on the right ofthe abnormal one until stager9 is reached, after which stage 0 isactivated, through lead 113, to begin the cycle anew on the next pulse.

It will be obvious that at each stage of the counter voltages areavailable for actuating other elements of the computer as desired, inthe form of static positive or negative voltages or else voltage pulseswhich change respectively to negative or positive as each stage changesits state.

Referring now to FIG. 2, the pulse standardizer for applying inputpulses to line 99 is shown. It has been mentioned that in the operationof a counter it is necessary that the input pulses have a certain shapeand magnitude. Distortion of pulses because of the capacitance ofinterconnecting circuits and because of passage through variousgatetubes makes it necessary to use a pulsestandardizing means betweensome of the circuits. A means adapted includes a flip-flop in which oneof its states is only semi-stable.

After an input pulse has flipped the circuit from the stable state shownin FIG. 2, with all tubes reversed in state, it will flip back to itsoriginal state in a time determined by the circuit constants andpractically independent of the input pulse.

The explanation of this action is as follows: the values of resistorsA56, A57 and A58 are such that when tube A60 is conducting the potentialdrop across resistance A57 causes biasing of the' tube A61 at itscathode to cut-off, aided by the'condition already existing atthe gridof tube A61 due to conduction at the first tube A62. A negative pulse isthen applied to the input-the grid of 4. tube A62, to diminish the flowof current through the said tube A62, impressing a positive-going signalon the control grid of the tube A61 to initiate the flow of currentproducing a negative going potential excursion at the anode terminal ofthe resistor A59 which cuts off tube A60. Then, after a time whichdepends on the product 7 A59, A53, tube A60 is no longer biased tocut-off and as it begins to conduct, the increased current and higherpotential across resistance A57, acting on cathode of tube A61 begins tobias tube A61 to cut-off again, This change in tube A51 involves a risein its plate potential which reacts on the control grid of tube A60, andthe action is accelerated, bringing tube A to full conduction, flippingthe circuit back to its original state.

This standardizer includes in its plate circuit an inductance A64, inthe present instance a choke of 5 mh. t re erTect of which on cut-off oftube A60 is to augment the rise of potential at the plate.

This rise in potential is transmitted through A65 to the control grid ofA66, causing it to conduct. The duration of this positive signal appliedto A66 is almost entirely determined by the parameters A64,.A65 and A67and certain operating voltages, since tube A60 remains non-conductingduring this interval. A negative pulse is therefore generated at theplate of tube A66 and appears at the output. Since tubes A61 and A60constitute a modified flip-flop, it is important to note that theeffective plate electrode of tube A60 for this flip-flop action is thescreen grid electrode which is held at a fixed potential, and thepotential changes of the actual plate electrode of tube A60 havenegligible eifect on the flip-flop. action. The time constant of theflip-flop circuit is made large enough by choice of condenser A63 sothat tube A60 will.

However, when this occurs no output pulse will be gen-- erated becausethe initiation of conduction in tube A60 will apply a negative pulse tothe control grid of A66, 0

and this tube has already returned to a non-conducting state withthedecay of potential across the inductor 64.

As a matter of policy the grids in all the tubes such as described inthe rings, stoppers, gates, inverters, cathode followers, pulsestandardizers and the like, throughout the Eniac, are driven tosaturation when the tubes are on and they receive biasing potentialsexceeding the cut ofi? bias potential by factors of three to four whenoff. This means the circuits are not amplitude-sensitive, that is, aconsiderable change in supply potentials and in tube conductance (asmight be due to aging) will not affect the reliability of operation. 7

It should be appreciated that the inherent result of the particularorganization of elements in the pulse standardizer of FIG. 2, not onlyproduces a definite pulse of high elfectiveness in relation to theinitiating pulse to which is responds, but it is also organized withtime constant values definitely related to the internal time constantsof the ring circuit, so that the speed of response a details, has amongothers, also the following highly important advantages contributingfurther to the durability of the machine, its certainty of mathematicaloperation (so that successive identical computations will renderidentical numerical results):

(1) Relieves the grids of the capacity loading of the pulse inputcircuits.

(2) Allows the use of smaller power to drive the ring circuit.

(3) Prevents undesired modes of counting by the degeneration effectresulting f om the operation of the activated tubes. 7

(4) Pulsing the cathode by a negative pulse permits 5 obtaining thepulse from the plate of a drive tube rather than from the cathode, sothat the driver tube is not degenerated.

Although only a certain and specific embodiment of this invention hasbeen shown and described, it will be understood that this invention isnot to be limited except insofar as is indicated by the scope of theappended claims.

What is claimed is:

1. A counter-ring comprising a plurality of pairs of electronicdischarge devices A and B, respectively, each device having at least ananode and cathode and a control grid, each pair being interconnected asa trigger pair only one device of which may be conducting at any giventime, so that when A of a given pair is conducting and B non-conducting,a suitable cathode pulse applied to the cathode of A is effective tointerchange the conducting and the non-conducting states of the pairfrom state A conducting to state B conducting, connections between eachsaid pair and an electrically adjacent pair for transmitting atriggering pulse from any one pair to the adjacent pair to change itsconducting state from B to A when the said pair changes from the Aconducting state to the B conducting state, a common pulse input circuitconnected to the A cathode of each pair and circuit parameters for saiddevices of such value that only one of any adjacent pairs is in the Aconducting state at any given time, and inductive means connected to anactive element means in intimate electrical association with saidcounterring for receiving pulses to be counted and reshaping saidreceived pulses to produce pulses of optmium characteristics fordefinite triggering of said counter-ring at maximum rate wherebyreceived pulses may be accurately counted at optimum speed irrespectiveof wide variation in characteristics of said pulses as received.

2. In a counter or stepper ring for computing systems of the characterdescribed, a ring of trigger circuits each including two electron tubetriodes each having its grid reactively coupled with the plates of theother, a B source symmetricaly connected to the anodes and cathodes;said ring characterized by a resistance in the plate supply exceedinglyhigh as compared to conventional practice in trigger circuits, and agrid-plate coupling resistance parallel to said reactance coupling whichis exceedingly low as compared to conventional practice in triggercircuits, said counter or stepper ring including inductive means andactive element means connected for applying a sharp negative pulsecommonly to the cathodes of the tubes of the ring, and having a markedlylower potential not less than double that required to fire the triode.

No references cited.

1. A COUNTER-RING COMPRISING A PLURALITY OF PAIRS OF ELECTRONICDISCHARGE DEVICES A AND B, RESPECTIVELY, EACH DEVICE HAVING AT LEAST ANANODE AND CATHODE AND A CONTROL GRID, EACH PAIR BEING INTERCONNECTED ASA TRIGGER PAIR ONLY ONE DEVICE OF WHICH MAY BE CONDUCTING AT ANY GIVENTIME, SO THAT WHEN A OF A GIVEN PAIR IS CONDUCTING AND B NON-CONDUCTING,A SUITABLE CATHODE PULSE APPLIED TO THE CATHODE OF A IS EFFECTIVE TOINTERCHANGE THE CONDUCTING AND THE NON-CONDUCTING STATES OF THE PAIRFROM STATE A CONDUCTING TO STATE B CONDUCTING, CONNECTIONS BETWEEN EACHSAID PAIR AND AN ELECTRICALLY ADJACENT PAIR FOR TRANSMITTING ATRIGGERING PULSE FROM ANY ONE PAIR TO THE ADJACENT PAIR TO CHANGE ITSCONDUCTING STATE FROM B TO A WHEN THE SAID PAIR CHANGES FROM THE ACONDUCTING STATE TO THE B CONDUCTING STATE, A COMMON PULSE INPUT CIRCUITCONNECTED TO THE A CATHODE OF EACH PAIR AND CIRCUIT PARAMETERS FOR SAIDDEVICES OF SUCH VALUE THAT ONLY ONE OF ANY ADJACENT PAIRS IS IN THE ACONDUCTING STATE AT ANY GIVEN TIME, AND INDUCTIVE MEANS CONNECTED TO ANACTIVE ELEMENT MEANS IN INTIMATE ELECTRICAL ASSOCIATION WITH SAIDCOUNTERRING FOR RECEIVING PULSES TO BE COUNTED AND RESHAPING SAIDRECEIVED PULSES TO PRODUCE PULSES OF OPTMIUM CHARACTERISTICS FORDEFINITE TRIGGERING OF SAID COUNTER-RING AT MAXIMUM RATE WHEREBYRECEIVED PULSES MAY BE ACCURATELY COUNTED AT OPTIMUM SPEED IRRESPECTIVEOF WIDE VARIATION IN CHARACTERISTICS OF SAID PULSES AS RECEIVED.